1 /****************************************************************************
2  * Copyright 2018-2020,2021 Thomas E. Dickey                                *
3  * Copyright 1998-2014,2016 Free Software Foundation, Inc.                  *
4  *                                                                          *
5  * Permission is hereby granted, free of charge, to any person obtaining a  *
6  * copy of this software and associated documentation files (the            *
7  * "Software"), to deal in the Software without restriction, including      *
8  * without limitation the rights to use, copy, modify, merge, publish,      *
9  * distribute, distribute with modifications, sublicense, and/or sell       *
10  * copies of the Software, and to permit persons to whom the Software is    *
11  * furnished to do so, subject to the following conditions:                 *
12  *                                                                          *
13  * The above copyright notice and this permission notice shall be included  *
14  * in all copies or substantial portions of the Software.                   *
15  *                                                                          *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
18  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
19  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
22  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
23  *                                                                          *
24  * Except as contained in this notice, the name(s) of the above copyright   *
25  * holders shall not be used in advertising or otherwise to promote the     *
26  * sale, use or other dealings in this Software without prior written       *
27  * authorization.                                                           *
28  ****************************************************************************/
29 
30 /****************************************************************************
31  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
32  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
33  *     and: Juergen Pfeifer                         1997                    *
34  *     and: Sven Verdoolaege                        2000                    *
35  *     and: Thomas E. Dickey                        1996-on                 *
36  ****************************************************************************/
37 
38 #include <curses.priv.h>
39 
40 MODULE_ID("$Id: lib_bkgd.c,v 1.62 2021/02/13 20:06:54 tom Exp $")
41 
42 static const NCURSES_CH_T blank = NewChar(BLANK_TEXT);
43 
44 /*
45  * Set the window's background information.
46  */
47 #if USE_WIDEC_SUPPORT
48 NCURSES_EXPORT(void)
49 #else
50 static NCURSES_INLINE void
51 #endif
52 wbkgrndset(WINDOW *win, const ARG_CH_T ch)
53 {
54     T((T_CALLED("wbkgrndset(%p,%s)"), (void *) win, _tracech_t(ch)));
55 
56     if (win) {
57 	attr_t off = AttrOf(win->_nc_bkgd);
58 	attr_t on = AttrOf(CHDEREF(ch));
59 
60 	toggle_attr_off(WINDOW_ATTRS(win), off);
61 	toggle_attr_on(WINDOW_ATTRS(win), on);
62 
63 #if NCURSES_EXT_COLORS
64 	{
65 	    int pair;
66 
67 	    if ((pair = GetPair(win->_nc_bkgd)) != 0)
68 		SET_WINDOW_PAIR(win, 0);
69 	    if ((pair = GetPair(CHDEREF(ch))) != 0)
70 		SET_WINDOW_PAIR(win, pair);
71 	}
72 #endif
73 
74 	if (CharOf(CHDEREF(ch)) == L('\0')) {
75 	    SetChar(win->_nc_bkgd, BLANK_TEXT, AttrOf(CHDEREF(ch)));
76 	    if_EXT_COLORS(SetPair(win->_nc_bkgd, GetPair(CHDEREF(ch))));
77 	} else {
78 	    win->_nc_bkgd = CHDEREF(ch);
79 	}
80 #if USE_WIDEC_SUPPORT
81 	/*
82 	 * If we're compiled for wide-character support, _bkgrnd is the
83 	 * preferred location for the background information since it stores
84 	 * more than _bkgd.  Update _bkgd each time we modify _bkgrnd, so the
85 	 * macro getbkgd() will work.
86 	 */
87 	{
88 	    cchar_t wch;
89 	    int tmp;
90 
91 	    memset(&wch, 0, sizeof(wch));
92 	    (void) wgetbkgrnd(win, &wch);
93 	    tmp = _nc_to_char((wint_t) CharOf(wch));
94 
95 	    win->_bkgd = (((tmp == EOF) ? ' ' : (chtype) tmp)
96 			  | (AttrOf(wch) & ALL_BUT_COLOR)
97 			  | (chtype) ColorPair(GET_WINDOW_PAIR(win)));
98 	}
99 #endif
100     }
101     returnVoid;
102 }
103 
104 NCURSES_EXPORT(void)
105 wbkgdset(WINDOW *win, chtype ch)
106 {
107     NCURSES_CH_T wch;
108     T((T_CALLED("wbkgdset(%p,%s)"), (void *) win, _tracechtype(ch)));
109     SetChar2(wch, ch);
110     wbkgrndset(win, CHREF(wch));
111     returnVoid;
112 }
113 
114 /*
115  * Set the window's background information and apply it to each cell.
116  */
117 static NCURSES_INLINE int
118 _nc_background(WINDOW *win, const ARG_CH_T ch, bool narrow)
119 {
120 #undef  SP_PARM
121 #define SP_PARM SP		/* to use Charable() */
122     int code = ERR;
123 
124 #if USE_WIDEC_SUPPORT
125     T((T_CALLED("%s(%p,%s)"),
126        narrow ? "wbkgd" : "wbkgrnd",
127        (void *) win,
128        _tracecchar_t(ch)));
129 #define TraceChar(c) _tracecchar_t2(1, &(c))
130 #else
131     T((T_CALLED("%s(%p,%s)"),
132        "wbkgd",
133        (void *) win,
134        _tracech_t(ch)));
135     (void) narrow;
136 #define TraceChar(c) _tracechar(CharOf(c))
137 #endif
138 
139     if (SP == 0) {
140 	;
141     } else if (win) {
142 	NCURSES_CH_T new_bkgd = CHDEREF(ch);
143 	NCURSES_CH_T old_bkgd;
144 	int y;
145 	NCURSES_CH_T old_char;
146 	attr_t old_attr;
147 	int old_pair;
148 	NCURSES_CH_T new_char;
149 	attr_t new_attr;
150 	int new_pair;
151 
152 	/* SVr4 trims color info if non-color terminal */
153 	if (!SP->_pair_limit) {
154 	    RemAttr(new_bkgd, A_COLOR);
155 	    SetPair(new_bkgd, 0);
156 	}
157 
158 	/* avoid setting background-character to a null */
159 	if (CharOf(new_bkgd) == 0) {
160 	    NCURSES_CH_T tmp_bkgd = blank;
161 	    SetAttr(tmp_bkgd, AttrOf(new_bkgd));
162 	    SetPair(tmp_bkgd, GetPair(new_bkgd));
163 	    new_bkgd = tmp_bkgd;
164 	}
165 
166 	memset(&old_bkgd, 0, sizeof(old_bkgd));
167 	(void) wgetbkgrnd(win, &old_bkgd);
168 
169 	if (!memcmp(&old_bkgd, &new_bkgd, sizeof(new_bkgd))) {
170 	    T(("...unchanged"));
171 	    returnCode(OK);
172 	}
173 
174 	old_char = old_bkgd;
175 	RemAttr(old_char, ~A_CHARTEXT);
176 	old_attr = AttrOf(old_bkgd);
177 	old_pair = GetPair(old_bkgd);
178 
179 	if (!(old_attr & A_COLOR)) {
180 	    old_pair = 0;
181 	}
182 	T(("... old background char %s, attr %s, pair %d",
183 	   TraceChar(old_char), _traceattr(old_attr), old_pair));
184 
185 	new_char = new_bkgd;
186 	RemAttr(new_char, ~A_CHARTEXT);
187 	new_attr = AttrOf(new_bkgd);
188 	new_pair = GetPair(new_bkgd);
189 
190 	/* SVr4 limits background character to printable 7-bits */
191 	if (
192 #if USE_WIDEC_SUPPORT
193 	       narrow &&
194 #endif
195 	       !Charable(new_bkgd)) {
196 	    new_char = old_char;
197 	}
198 	if (!(new_attr & A_COLOR)) {
199 	    new_pair = 0;
200 	}
201 	T(("... new background char %s, attr %s, pair %d",
202 	   TraceChar(new_char), _traceattr(new_attr), new_pair));
203 
204 	(void) wbkgrndset(win, CHREF(new_bkgd));
205 
206 	/* SVr4 updates color pair if old/new match, otherwise just attrs */
207 	if ((new_pair != 0) && (new_pair == old_pair)) {
208 	    WINDOW_ATTRS(win) = new_attr;
209 	    SET_WINDOW_PAIR(win, new_pair);
210 	} else {
211 	    WINDOW_ATTRS(win) = new_attr;
212 	}
213 
214 	for (y = 0; y <= win->_maxy; y++) {
215 	    int x;
216 
217 	    for (x = 0; x <= win->_maxx; x++) {
218 		NCURSES_CH_T *cp = &(win->_line[y].text[x]);
219 		int tmp_pair = GetPair(*cp);
220 		attr_t tmp_attr = AttrOf(*cp);
221 
222 		if (CharEq(*cp, old_bkgd)) {
223 #if USE_WIDEC_SUPPORT
224 		    if (!narrow) {
225 			if (Charable(new_bkgd)) {
226 			    SetChar2(*cp, CharOf(new_char));
227 			} else {
228 			    SetChar(*cp, L' ', AttrOf(new_char));
229 			}
230 			memcpy(cp->chars,
231 			       new_char.chars,
232 			       CCHARW_MAX * sizeof(cp->chars[0]));
233 		    } else
234 #endif
235 			SetChar2(*cp, CharOf(new_char));
236 		}
237 		if (tmp_pair != 0) {
238 		    if (tmp_pair == old_pair) {
239 			SetAttr(*cp, (tmp_attr & ~old_attr) | new_attr);
240 			SetPair(*cp, new_pair);
241 		    } else {
242 			SetAttr(*cp,
243 				(tmp_attr & (~old_attr | A_COLOR))
244 				| (new_attr & ALL_BUT_COLOR));
245 		    }
246 		} else {
247 		    SetAttr(*cp, (tmp_attr & ~old_attr) | new_attr);
248 		    SetPair(*cp, new_pair);
249 		}
250 	    }
251 	}
252 	touchwin(win);
253 	_nc_synchook(win);
254 	code = OK;
255     }
256     returnCode(code);
257 }
258 
259 #if USE_WIDEC_SUPPORT
260 NCURSES_EXPORT(int)
261 wbkgrnd(WINDOW *win, const ARG_CH_T ch)
262 {
263     return _nc_background(win, ch, FALSE);
264 }
265 #endif
266 
267 NCURSES_EXPORT(int)
268 wbkgd(WINDOW *win, chtype ch)
269 {
270     NCURSES_CH_T wch;
271     SetChar2(wch, ch);
272     return _nc_background(win, CHREF(wch), TRUE);
273 }
274